Bile acids are not only physiological detergents facilitating nutrient absorption, but also signaling molecules regulating metabolic homeostasis. We reported recently that transgenic expression of CYP7A1 in mice stimulated bile acid synthesis and prevented Western diet-induced obesity, insulin resistance and hepatic steatosis. The aim of this experiment is to determine the impact of induction of hepatic bile acid synthesis on liver metabolism by determining hepatic gene expression profile in CYP7A1 transgenic mice. CYP7A1 transgenic mice and wild type control mice were fed either standard chow diet or high fat high cholesterol Western diet for 4 month. Hepatic gene expressions were measured by microarray analysis. Our results indicate that hepatic bile acid synthesis is closely linked to cholesterogenesis and lipogenesis, and maintaining bile acid homeostasis is improtant in hepatic metabolic homeostasis.
Regulation of cholesterol and bile acid homeostasis by the cholesterol 7α-hydroxylase/steroid response element-binding protein 2/microRNA-33a axis in mice.
Sex, Age, Specimen part
View SamplesNatural killer (NKT) T cells exhibit tissue distribution, surface phenotype, and functional responses that are strikingly different from those of conventional T cells. The transcription factor PLZF is responsible for most of these properties, as its ectopic expression in conventional T cells is sufficient to confer to them an NKT-like phenotype. The molecular program downstream of PLZF, however, is largely unexplored.
PLZF Controls the Expression of a Limited Number of Genes Essential for NKT Cell Function.
Sex, Specimen part
View SamplesWe have determined the consequences of ICN1 overexpression from retroviral vectors introduced into bone marrow cells.
Oncogenesis of T-ALL and nonmalignant consequences of overexpressing intracellular NOTCH1.
No sample metadata fields
View SamplesSomatic hypermutation (SHM) and class switch recombination (CSR) increase the affinity and diversify the effector functions of antibodies during immune responses. Although SHM and CSR are fundamentally different, their independent roles in regulating B cell fate have been difficult to uncouple because a single enzyme, activation-induced cytidine deaminase (encoded by Aicda), initiates both reactions. Here, we used a combination of Aicda and antibody mutant alleles that separate the effects of CSR and SHM on polyclonal immune responses. We found that class-switching to IgG1 biased the fate choice made by B cells, favoring the plasma cell over memory cell fate without significantly affecting clonal expansion in the germinal center (GC). In contrast, SHM reduced the longevity of memory B cells by creating polyreactive specificities that were selected against over time. Our data define the independent contributions of SHM and CSR to the generation and persistence of memory in the antibody system. Overall design: IgG1 and IgM light zone (LZ) and dark zone (DZ) germinal center (GC) B cells were compared in immunized AIDcre/- IgH-96K/+ R26-LSL-YFP mice.
Independent Roles of Switching and Hypermutation in the Development and Persistence of B Lymphocyte Memory.
Specimen part, Cell line, Subject
View SamplesSomatic hypermutation (SHM) and class switch recombination (CSR) increase the affinity and diversify the effector functions of antibodies during immune responses. Although SHM and CSR are fundamentally different, their independent roles in regulating B cell fate have been difficult to uncouple because a single enzyme, activation-induced cytidine deaminase (encoded by Aicda), initiates both reactions. Here, we used a combination of Aicda and antibody mutant alleles that separate the effects of CSR and SHM on polyclonal immune responses. We found that class-switching to IgG1 biased the fate choice made by B cells, favoring the plasma cell over memory cell fate without significantly affecting clonal expansion in the germinal center (GC). In contrast, SHM reduced the longevity of memory B cells by creating polyreactive specificities that were selected against over time. Our data define the independent contributions of SHM and CSR to the generation and persistence of memory in the antibody system. Overall design: IgG1 and IgM light zone (LZ) germinal center (GC) B cells that were Nurr77-GFP+ or Nurr77-GFP- were compared in immunized AIDcre/- IgH-96K/+ Nurr77-GFP mice.
Independent Roles of Switching and Hypermutation in the Development and Persistence of B Lymphocyte Memory.
Specimen part, Cell line, Subject
View SamplesNoncommunicable chronic respiratory diseases (CRDs) such as chronic obstructive pulmonary disease (COPD) and asthma affect hundreds of millions of people and are associated with increasing morbidity and mortality. CRDs are multifactorial disorders and despite different etiologies they commonly manifest in pulmonary structural (airway remodeling, emphysema) and/or functional changes. In this study we used mice intrinsically developing autoimmune-mediated lung inflammation associated with lung pathology and immune imprinting partly comparable to hallmarks of CRD. The so called SPC-HAxTCR-HA transgenic mice (BALB/c genetic background), express a neo-self antigen (influenza A virus hemagglutinin, HA) on lung alveolar epithelial type II cells in the presence of HA-specific CD4+ T cells leading to the establishment of chronic lung inflammation. In order to characterize the inflammatory lung milieu of SPC-HAxTCR-HA mice in comparison to SPC-HA control mice (lacking HA-specific CD4+ T cells), we performed whole lung tissue transcriptional analyses (n = 3 / group). 378 transcripts were found to be differentially expressed in SPC-HAxTCR-HA lungs. 326 of those were up-regulated and 52 were down-regulated compared to SPC-HA control mice.
Chronic lung inflammation primes humoral immunity and augments antipneumococcal resistance.
Sex, Age, Specimen part
View SamplesAberrations in genes coding for subunits of the BAF chromatin remodeling complex are highly abundant in human cancers. Currently, it is not understood how these loss-of-function mutations contribute to cancer development and how they can be targeted therapeutically. The cancer type specific occurrence patterns of certain subunit mutations suggest subunit-specific effects on BAF complex function, possibly by the formation of aberrant residual complexes. Here, we systematically characterize the effects of individual subunit loss on complex composition, chromatin accessibility and gene expression in a panel of knock-out cell lines deficient for 22 targetable BAF subunits. We observe strong, specific and often discordant alterations dependent on the targeted subunit and show that these explain intra-complex co-dependencies, including the novel synthetic lethal interactions SMARCA4-ARID2, SMARCA4-ACTB and SMARCC1-SMARCC2. These data provide insights into the role of different BAF subcomplexes in genome-wide chromatin organization and suggest novel approaches to therapeutically target BAF mutant cancers. Overall design: RNA-seq samples for knockouts of BAF complex in the HAP1 cell line.
Systematic characterization of BAF mutations provides insights into intracomplex synthetic lethalities in human cancers.
Cell line, Subject
View SamplesActivation of b-catenin has been causatively linked to the etiology of colon cancer. Conditional stabilization of this molecule in pro-T-cells promotes thymocyte development without the requirement for preTCR signaling. We show here that activated b-catenin stalls the developmental transition from the double-positive (DP) to the single-positive (SP) thymocyte stage and predisposes DP thymocytes to transformation. b-Catenin induced thymic lymphomas have a leukemic arrest at the early DP stage. Lymphomagenesis requires Rag activity, which peaks at this developmental stage, as well as additional secondary genetic events. A consistent secondary event is the transcriptional upregulation of c-Myc, whose activity is required for transformation since its conditional ablation abrogates lymphomagenesis. In contrast, the expression of Notch receptors as well as targets is reduced in DP thymocytes with stabilized b-catenin and remains low in the lymphomas indicating that Notch activation is not required or selected for in b-catenin induced lymphomas. Thus, b-catenin activation may provide a mechanism for the induction of T-ALL that does not depend on Notch activation.
Beta-catenin stabilization stalls the transition from double-positive to single-positive stage and predisposes thymocytes to malignant transformation.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The requirement for cyclin D function in tumor maintenance.
Specimen part, Cell line
View SamplesD-cyclins represent components of cell cycle machinery. To test the efficacy of targeting D-cyclins in cancer treatment, we engineered mouse strains which allow acute and global ablation of individual D-cyclins in a living animal. Ubiquitous shutdown of cyclin D1 or inhibition of cyclin D associated kinase activity in mice bearing ErbB2-driven mammary carcinomas halted cancer progression and triggered tumor-specific senescence, without compromising the animals' health. Ablation of cyclin D3 in mice bearing T-cell acute lymphoblastic leukemias (T-ALL) triggered tumorspecific apoptosis. Such selective killing of leukemic cells can be also achieved by inhibiting cyclin D associated kinase activity in mouse and human T-ALL models. Hence, contrary to what one might expect from ablation of a cell cycle protein, acute shutdown of a D-cyclin leads not only to cell cycle arrest, but it also triggers tumor cell senescence or apoptosis, and it affects different tumor types through distinct cellular mechanisms. Inhibiting cyclin D-activity represents a highly-selective anticancer strategy which specifically targets cancer cells without significantly affecting normal tissues.
The requirement for cyclin D function in tumor maintenance.
Cell line
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